1. Field of the Invention
The present invention relates to a cleaning device for use in an electrophotographic image forming apparatus, a process cartridge which is detachably mountable to a main body of the electrophotographic image forming apparatus, a cleaning member for use in the process cartridge, and the electrophotographic image forming apparatus.
Here, an electrophotographic image forming apparatus is an image forming apparatus for forming an image on a recording medium (such as a paper or an OHP sheet) through an electrophotographic image forming process. As for examples of the electrophotographic image forming apparatus, for example, there are known an electrophotographic copying machine, an electrophotographic printer (such as a laser printer or an LED printer), facsimile equipment, a word processor, and a complex machine thereof (such as a multi-function printer).
2. Related Background Art
Heretofore, in the electrophotographic image forming apparatus as described above, an electrophotographic photosensitive member which is uniformly charged with electricity by charging means is subjected to selective exposure to thereby form an electrostatic latent image on the surface of the electrophotographic photosensitive member. Then, the electrostatic latent image is developed by developing means to obtain a visible image (developer image). Thereafter, the developer image is transferred to a recording paper (recording medium). Thus, an image is formed on the recording paper.
A developer remaining on the surface of the electrophotographic photosensitive member after the developer image is transferred to the recording paper is removed by cleaning means. Then, the operation proceeds to the next image formation.
Note that the developer which has been removed from the surface of the electrophotographic photosensitive member by the cleaning means is contained in a removed developer containing portion.
Now, in order that a cleaning blade used as the cleaning means may exhibit a sufficient cleaning effect, an edge portion of an elastic blade member must abut against the surface of the electrophotographic photosensitive member with high positional precision. When an inroad amount and an abutting angle of the edge portion of the elastic blade member with respect to the electrophotographic photosensitive member are not appropriate, there is a possibility that the developer remaining on the surface of the electrophotographic photosensitive member can not be sufficiently scraped off.
As a cause of such phenomena, it is conceivable that a sheet metal supporting the elastic blade member is deformed due to a deviation in the attachment position of the cleaning blade, and the sheet metal supporting the elastic blade member has insufficient strength.
As means for solving the problem of the insufficient strength of the sheet metal, thickening of the sheet metal has been conventionally adopted. However, this method is disadvantageous from the viewpoints of cost and lightening of the image forming apparatus. In addition, as another means, bending of the sheet metal is also performed in order to increase the strength of the sheet metal (refer to JP H07-175393 A and JP H06-95502 A).
In addition, in recent years, a demand for color electrophotographic image forming apparatuses, which can form a color image on a recording medium, has increased. Of those color electrophotographic image forming apparatuses, for example, a color electrophotographic image forming apparatus of a tandem system, in which drum-shaped electrophotographic photosensitive members, i.e., photosensitive drums, are disposed in a line in order to form developer images of yellow (Y), magenta (M), cyan (C) and black (B), has been put into practical use.
In particular, in a color electrophotographic image forming apparatus of a vertical tandem system in which a plurality of photosensitive drums are disposed in parallel in the vertical direction, in order to reduce a height of the electrophotographic image forming apparatus, the height of the removed developer containing portion must also be reduced.
As described above, compactness as well as high speed and high image quality are required for recent image forming apparatuses.
In order to meet this requirement, miniaturization is required for a main body of the image forming apparatus, and a process cartridge (cleaning device) occupying a large space within the image forming apparatus.
From this viewpoint, there is required miniaturization of components or parts constituting the process cartridge (cleaning device) and efficient placement of these components or parts.